russau/WebForm1.aspx

## WebForm1.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="DynamicControls.WebForm1" %>

<%@ Register src="WebUserControl1.ascx" tagname="WebUserControl1" tagprefix="uc1" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    <asp:DropDownList ID="ddl" runat="server" AutoPostBack=true>
        <asp:ListItem>qwerty</asp:ListItem>
        <asp:ListItem>qabcwerty</asp:ListItem>
    </asp:DropDownList>
    <asp:Label ID="lbl" runat="server" />
    <asp:Button Text="go" runat="server"/>
    <hr />

    <table id="tbl" runat="server">
    </table>

    </div>
    </form>
</body>
</html>

## WebForm1.aspx.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

namespace DynamicControls
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                lbl.Text = "kkk";
                ViewState["def"] = "ghi";
                BuildDataEntry();
            }

        }

        protected override void LoadViewState(object savedState)
        {
            base.LoadViewState(savedState);
            BuildDataEntry();
        }

        protected override object SaveViewState()
        {
            object o = base.SaveViewState();
            return o;
        }

        void BuildDataEntry()
        {
            string selected = Request.Form["ddl"] ?? ddl.SelectedValue as string;
            foreach (var c in selected.ToCharArray())
            {
                var row = new HtmlTableRow();
                var cell = new HtmlTableCell();
                cell.InnerHtml = c.ToString();

                if (c != 't')
                {
                    TextBox textbox = new TextBox();
                    textbox.ID = c + "txt";
                    textbox.Text = c + "val";
                    cell.Controls.Add(textbox);

                }
                else
                {
                    DropDownList dll2 = new DropDownList();

                    dll2.ID = c + "ddl";
                    dll2.DataSource = new string[] { "aaa", "bbb", "ccc" };
                    dll2.DataBind();
                    cell.Controls.Add(dll2);

                    // disabling a control must store something in the viewstate control tree
                    // that causes a crash when other controls are inserted above this one
                    // EnableViewState = false fixes the problem
                    //dll2.EnableViewState = false;
                    dll2.Enabled = false;
                }

                row.Cells.Add(cell);
                tbl.Rows.Add(row);
            }
        }
    }
}
	<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="DynamicControls.WebForm1" %>

	<%@ Register src="WebUserControl1.ascx" tagname="WebUserControl1" tagprefix="uc1" %>

	<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

	<html xmlns="http://www.w3.org/1999/xhtml">
	<head runat="server">
	<title></title>
	</head>
	<body>
	<form id="form1" runat="server">
	<div>
	<asp:DropDownList ID="ddl" runat="server" AutoPostBack=true>
	<asp:ListItem>qwerty</asp:ListItem>
	<asp:ListItem>qabcwerty</asp:ListItem>
	</asp:DropDownList>
	<asp:Label ID="lbl" runat="server" />
	<asp:Button Text="go" runat="server"/>
	<hr />

	<table id="tbl" runat="server">
	</table>

	</div>
	</form>
	</body>
	</html>
	using System;
	using System.Collections.Generic;
	using System.Linq;
	using System.Web;
	using System.Web.UI;
	using System.Web.UI.WebControls;
	using System.Web.UI.HtmlControls;

	namespace DynamicControls
	{
	public partial class WebForm1 : System.Web.UI.Page
	{
	protected void Page_Load(object sender, EventArgs e)
	{
	if (!IsPostBack)
	{
	lbl.Text = "kkk";
	ViewState["def"] = "ghi";
	BuildDataEntry();
	}

	}

	protected override void LoadViewState(object savedState)
	{
	base.LoadViewState(savedState);
	BuildDataEntry();
	}

	protected override object SaveViewState()
	{
	object o = base.SaveViewState();
	return o;
	}

	void BuildDataEntry()
	{
	string selected = Request.Form["ddl"] ?? ddl.SelectedValue as string;
	foreach (var c in selected.ToCharArray())
	{
	var row = new HtmlTableRow();
	var cell = new HtmlTableCell();
	cell.InnerHtml = c.ToString();

	if (c != 't')
	{
	TextBox textbox = new TextBox();
	textbox.ID = c + "txt";
	textbox.Text = c + "val";
	cell.Controls.Add(textbox);

	}
	else
	{
	DropDownList dll2 = new DropDownList();

	dll2.ID = c + "ddl";
	dll2.DataSource = new string[] { "aaa", "bbb", "ccc" };
	dll2.DataBind();
	cell.Controls.Add(dll2);

	// disabling a control must store something in the viewstate control tree
	// that causes a crash when other controls are inserted above this one
	// EnableViewState = false fixes the problem
	//dll2.EnableViewState = false;
	dll2.Enabled = false;
	}

	row.Cells.Add(cell);
	tbl.Rows.Add(row);
	}
	}
	}
	}